Mean walking time (± SD; n = 50) of naive females of Theocolax elegans in a four chamber olfactometer. GM: areas above Petri dishes with 20 pheromone-releasing S. zeamais males on 100 healthy grains, GF: areas above Petri dishes with 20 unmated S. zeamais females on 100 healthy grains, C: areas above control Petri dishes. Bars with different letters are significantly different at P < 0.05 (Friedman ANOVA followed by Wilcoxon-Wilcox-test for multiple comparisons).